Database Reference
In-Depth Information
Restoring and Recovering to Different Server
When you think about architecting your backup strategy, as part of the process, you must also consider how you're
going to restore and recover. Your backups are only as good as the last time you tested a restore and recovery. A
backup strategy can be rendered worthless without a good restore-and-recovery strategy. The last thing you want to
happen is to have a media failure, go to restore your database, and then find out you're missing critical pieces, you
don't have enough space to restore, something is corrupt, and so on.
One of the best ways to test an RMAN backup is to restore and recover it to a different database server. This
will exercise all your backup, restore, and recovery DBA skills. If you can restore and recover an RMAN backup on a
different server, it will give you confidence when a real disaster hits. You can think of all the prior material in this topic
as the building blocks for performing technically challenging tasks. Moving a database from one server to another
using an RMAN backup requires an expert level understanding of the Oracle architecture and how B&R works.
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rMaN does have a
DUPLICATE DATABASE
command, which works well for copying a database from one server
to another. If you're going to be performing this type of task often, I would recommend that you use rMaN's duplicate
database functionality. however, you may still have to copy a backup of a database manually from one server to another,
especially when the security is such that you can't directly connect a production server to a development environment.
I work with many production databases in which there is no direct access to a production server, so the only way to
duplicate a database is by manually copying the rMaN backups from production to a test environment. starting with
oracle 11g release 2, you can use rMaN to duplicate a database based on backups you copy from the target to the
auxiliary server. see Mos note 874352.1 for details on targetless duplication.
Note
In this example the originating server and destination server have different mount points. Listed next are the
high-level steps required to take an RMAN backup and use it to recreate a database on a separate server:
1.
Create an RMAN backup on the originating database.
2.
Copy the RMAN backup to the destination server. All steps that follow are performed on
the destination database server.
3.
Ensure that Oracle is installed.
4.
Source the required OS variables.
Create an
init.ora
file for the database to be restored.
5.
6.
Create any required directories for data files, control files, and dump/trace files.
7.
Start up the database in nomount mode.
8.
Restore the control file from the RMAN backup.
9.
Start up the database in mount mode.
10.
Make the control file aware of the location of the RMAN backups.
11.
Rename and restore the data files to reflect new directory locations.
12.
Recover the database.
13.
Set the new location for the online redo logs.
